Under the term of the spine deformity are herein understood scolioses (abnormal curvatures of the spine in the sagital plane) and pathological kyphoses and lordoses (abnormal curvatures in the sagital plane). The operative correction of spine deformities by means of metal implants made of special stainless biocompatible steels and titanium alloys, represents the most effective manner of medical treatment of spine deformities and at the same time, a medico-technical problem which is being actual practically already one century, and which still has not been solved with satisfaction. Actually are known several principal constructive solutions for implants to treat spine deformities but each of them has, in addition to certain advantages, also a series of insufficiences. The whole set of known solutions may be divided into three basic groups which may be characterized in the following manner.
The first group represents a set of solutions which may be characterized as rigid systems. A significant feature of these systems is that they contain at least one rod or a plate which is introduced by an operation on the place of a spine deformity, almost in parallel with the spine, while in its whole lenght it is connected with at least two spinal vertebrae by various shaped fixing elements (hooks, clamps, screws, wire knots, etc) installed on it which are fixed on the body or the processus or the laminae of vertebrae. Usually two rods are used which are mutually in at least two spots interconnected and operationally installed along the sides of the spine while several or all vertebrae are then connected with them in its deformity place. From the functional point of view occurs the correction of the deformity by acting, regarding the long spinal axis, of cross tensile and/or pressure forces on deformed vertebrae while is made use of the rigidity of the rod or rods. These systems usually well correct and also stabilize the spine in all three planes but they do not allow the motion and the growth of stabilized segments. Therefore, when applying them, the joints are abolished by an operation and by putting on bone grafts will be evoked that the spine will grow together (spondylodesis, fusion) in the deformity place and that will locally prevent its growth and the mobility will be annulled. Presently, it is possible to insert here as representatives, for instance, of the Wisconsin instrumentations Drummond D. S., J. Pediatr. Orthop., 4,1984, 397-404; Drummond D. S., The Orthop. Clin. of North Am., 2, 1988, 208-289!, Cotrel-Dubousset Cotrel Y., Dubousset J., Rev. Chir. Orthop., 70, 1984, 489-495; Cotrel Y., Dubousset J., Orthop. Trans., 9, 1985, 118!, TSRH, the Isola system using the rod combined with the plate Asher M. A. et al.: Isola Spine Implant System: Principles and Practice, acroMed, Cleveland, 1991!, Central-Stab-System, the Luque instrumentation Luque E. R., Cardoso A., Orthop. Trans., 1, 1977, 136; Luque E. R.: Tailoring Surgery to Spinal Pathology. In Segmental Spinal Instrumentation. Thorofare, N.J., Slack Co., 1984! and others. This group may include also internal fixators (e.g. Socon (Socon-Fixateur Interne-Aesculap, Prospekt N. C-627 1091(3, Germany), Kluger's fixator DE P321957.3; Dick W. et al., Paraplegia, 23, 1985, 225-232!, Matzen's fixator Internal Fixator for the Lumbar Spine acc. to Matzen, Ulrich, Dr. HS (de Apr. 16, 1992 derer/e-matzen.pm.3! and others).
The second group is represented by systems which may be characterized as semirigid ones. For these instrumentations is typical that, they are made of:
a) The rod equipped at least at its ends with appropriately shaped fixing elements, which is by an operation applied from the concave or convex side of the deformity, and the fixing elements are fixed, under the actual maximum possible straightness of the spine deformity, on vertebrae in the area of the beginning and the end of a deformity, while from the functional point of view the correction of a deformity occurs by acting parallel expanding forces with the long spinal axis on its concave side or by acting pressing forces on its convex side; PA0 b) The wind spring equipped at its ends with appropriate fixing elements and which is applied by an operation from the convex side of the deformity, and the fixing elements are at actual tension of the spring fixed on vertebrae in the area of the beginning and the end of the deformity while from the functional point of view the correction of the deformity occurs by acting parallel forces with the long spinal axis on its convex side, PA0 c) From the combination of elements according to both previous points which may be also mutually interconnected while from the functional point of view the correction of the spinal deformity occurs by acting parallel compressing forces on its convex side and simultaneously by acting parallel distracting forces on its concave side. PA0 a) The rod of a constant lenght on which are fixed appropriate fixing elements so that the position of at least one element is adjustable in the long spinal axis direction. PA0 b) Two rods (the telescopic rod is made as a rod inserted by one its end into the coaxial tube) mutually interconnected on both ends, with fixing elements usually situated at the ends of rods, while the length of rods, and thus also the position of at least one fixing elements, is adjustable in the long spinal axis direction. PA0 1) A significant restriction, respectively, the total liquidation of the mobility and growth of the spine at minimum in the area of its deformity, PA0 2) The need to perform multiple operative interventions at their application on the growing spine what means a great load for the patient's organism.
Instrumentations belonging to the group of semirigid systems appropriately correct the spinal deformities and significantly or fully restrict the motion within the area of the spinal deformity only in the direction of acting correction forces. The spine is never corrected in all three planes (therefore, at their application the external fixation by the corset or jacket is always inevitable), but the instrumentations restrict the growth of the spine for at their application the joins are abolished by an operation and the spondylodesis is evoked. This group include, for instance, Allan's Allan F. G., J. Bone Joint Surgeon, 37(B, 1955, 92-96! and Kazmin's distractor, spiral springs according to Gruca Gruca A., Beitr. Orthop. u. Traumal., 5, 1958, 1-11; Gruca A., J. Bone Joint Surg., 40(A, 1958, 570-584!, their modification according to Weiss Weiss M., Bentkowsky Z., Clin. Orthop., 1974, 103-109!, Harrington's distraction and compression system Harrington P. R., J. Bone Joint Surg., 44(A, 1962, 591-610; Harrington P. R., Orthop. Clin. of North Am., 3, 1972, 49-67!, and others.
The third group may be characterized as telescopic systems which are characterized by the fact that they consist of:
The mentioned instrumentations are applied by an operation along the sides of the spinal deformity and through its fixing elements ensure the transfer of correcting forces on deformed spinal vertebrae. With the instrumentation according to the point a) it is possible, at periodically repeated operative interventions of a local scope, to change every time the position of at least one fixing element so that this position be brought into harmony with the growth of the spine. The instrumentation according to the point b) is spontaneously modified in the length in accordance with the growth of the spine. A significant disadvantage of these instrumentations is the minimalization of the scope of unevitable changes on the spine and the use of one and only once applied instrumentation by an operation for the period of the spinal growth. But, they have still a disadvantage characteristic for all the other, till now not mentioned solutions, i.e. significant restrictions of the spinal mobility. This group may actually include Harrington's distraction instrumentation Moe J. H., Orthop. Clin. of North Am., 3, 1972, 17-48! using a ratchet or threaded rods which does not assure the rotational stability, and therefore the external fixation of the spine by a corset or jacket is unevitable. The last system is Ulmer-Teleskop-Stab instrumentation used with the neuromuscular scolioses which stabilizes the spine in all three planes (the need of fixation by the corset or jacket is therefore not required), it corrects the deformity and at the same time, it follows telescopically its growth in the direction of its long axis.
From the above-mentioned facts it in obvious that all till present known solutions of devices for correcting spinal deformities have two significant disadvantages:
The aim of the submitted invention is to provide the medical practice such an instrumentation which will suppress these insufficiences to a maximum possible extent or which will fully eliminate them.